function wxImg(){
    var useragent = window.navigator.userAgent.toLowerCase();
           $('.btn_download,.aniBlow').click(function () {
               var d = document;
               var oShadow = d.getElementById('shadow');
               var scrollHeight = d.documentElement.scrollHeight || d.body.scrollHeight;

               if (useragent.match(/MicroMessenger/i) == 'micromessenger') {
                   oShadow.style.display = 'block';
                   oShadow.style.height = scrollHeight + 'px';
                   d.getElementById("weixinMsg").style.display = 'block';
               }
           $('#shadow').click(function(){
               $('#shadow').hide();
               $('#weixinMsg').hide();
           })
           })

}
$(function(){
	wxImg();
})